refactor: remove code smell java:S5786 (#2159)

https://sonarcloud.io/organizations/iluwatar/rules?open=java%3AS5786&rule_key=java%3AS5786

throttling/src/test/java/com/iluwatar/throttling/BarCustomerTest.java

@@ -33,7 +33,7 @@ import static org.junit.jupiter.api.Assertions.assertThrows;
 /**
  * TenantTest to test the creation of Tenant with valid parameters.
  */
-public class BarCustomerTest {
+class BarCustomerTest {
 
   @Test
   void constructorTest() {

throttling/src/test/java/com/iluwatar/throttling/BartenderTest.java

@@ -33,7 +33,7 @@ import org.junit.jupiter.api.Test;
 /**
  * B2BServiceTest class to test the B2BService
  */
-public class BartenderTest {
+class BartenderTest {
 
   private final CallsCount callsCount = new CallsCount();